A ligament is a piece of fibrous tissue which connects one bone to another, e.g., at a joint. Ligaments are frequently damaged (e.g., detached, torn, ruptured, etc.) as the result of injury and/or accident. A damaged ligament can impede proper motion of a joint and cause pain to the patient.
Various procedures have been developed to repair or replace a damaged ligament. The specific procedures used depend on the particular ligament which is to be restored and the nature and extent of the damage to the ligament.
The anterior cruciate ligament (ACL) of the knee is one ligament which is frequently damaged as the result of injury and/or accident. More particularly, and looking now at FIGS. 1 and 2, an ACL is shown extending across the interior of the knee, between the top of the tibia and the bottom of the femur. A damaged ACL can cause instability of the knee, may lead to arthritis and/or damage to other bodily structures, and can cause substantial pain for the patient.
Numerous procedures have been developed to replace a badly damaged ACL through a ligament replacement procedure. More particularly, and looking now at FIG. 3, these ACL replacement procedures generally involve drilling a bone tunnel across the tibia and up into the lower portion of the femur. Then a graft ligament, consisting of a harvested ligament or tendon or an artificial ligament, is passed through the tibial portion of the bone tunnel, across the interior of the joint, and up into the femoral portion of the bone tunnel. Then a distal portion of the graft ligament is secured in the femoral tunnel and a proximal portion of the graft ligament is secured in the tibial tunnel. Over time, the graft ligament osseointegrates with the host bones, providing an effective ligament restoration.
There are currently a variety of approaches to secure the graft ligament within the bone tunnel. These approaches typically depend on (i) whether the graft ligament is being fixed in the femoral tunnel or the tibial tunnel, and (ii) the type of graft ligament which is being used for the ligament replacement procedure.
More particularly, when the graft ligament is to be fixed in the femoral tunnel, the surgical apparatus must generally access the femoral tunnel from the base of the femur, and when the graft ligament is to be fixed in the tibial tunnel, the surgical apparatus must generally access the tibial tunnel from the front of the tibia. As a result, it is common for different types of surgical apparatus to be used, depending on whether the graft ligament is being secured in the femoral tunnel or in the tibial tunnel.
In addition to the foregoing, some ligament reconstruction procedures utilize a graft ligament which is harvested so as to include a portion of a bone block, e.g., a patellar tendon including a portion of the patella. Other ligament reconstruction procedures utilize a graft ligament which is harvested so as to consist entirely of soft tissue, e.g., a harvested hamstring tendon. In general, different types of surgical apparatus are used to secure the graft ligament in the bone tunnel, depending on whether the graft ligament includes a portion of a bone block or is composed entirely of soft tissue.
In practice, it is generally preferable to harvest graft ligaments consisting entirely of soft tissue, e.g., a hamstring tendon, since this is significantly less painful for the patient and reduces trauma to the harvest site. However, graft ligaments consisting entirely of soft tissue are generally more difficult to secure to the host bone, since the soft tissue is generally fairly soft and relatively slippery. In addition, the soft tissue tends to be biologically fragile, requiring greater care to ensure successful osseointegration.